What is synchronous detection of AM signal?

Synchronous detection is a measurement method where a stimulus is modulated with some frequency and the response is demodulated to bring the signal back down to base band.

What is synchronous detection in AM?

Synchronous detection is used for the detection or demodulation of Amplitude Modulation (AM). This form of modulation is still widely used for broadcasting on the long, medium and short wave bands despite the fact that there are more efficient forms of modulation that can be used today.

Can we apply synchronous detection method for demodulation of AM signal?

The simplest form of detection for an amplitude modulated signal utilises a simple diode rectifier. To achieve improved performance a form of demodulation known as synchronous demodulation can be used.

Why does synchronous detection of AM signal is considered as a disadvantage?

Explanation: Disadvantage of synchronous detection of AM signal are that it needs an additional system for generation of carrier. It also needs additional system for synchronization of carrier. Moreover receiver is complex and costly.

What is synchronous detection for SSB SC?

Here, the same carrier signal (which is used for generating SSBSC wave) is used to detect the message signal. Hence, this process of detection is called as coherent or synchronous detection.

Synchronous detection, AM detection in Communication Engineering by Engineering Funda

What is synchronous or coherent detection?

We assume that this locally generated carrier is exactly coherent or synchronized in both frequency and phase with the original carrier wave c(t) used to generate the DSB-SC wave . This method of detection is therefore called as coherent detection or synchronous detection .

What is synchronous or coherent detection why it is called coherent or synchronous?

Here, the same carrier signal (which is used for generating DSBSC signal) is used to detect the message signal. Hence, this process of detection is called as coherent or synchronous detection.

What are the methods for detecting AM waves?

Envelope detector is used to detect (demodulate) high level AM wave. Following is the block diagram of the envelope detector. This envelope detector consists of a diode and low pass filter. Here, the diode is the main detecting element.

Which of the following is used for AM detection?

The most common detector used in an AM radio broadcast receiver is: Coherent detector. Envelope detector. Ratio detector.

What are the advantages of AM over FM signal?

The advantages of AM radio are that it is relatively easy to detect with simple equipment, even if the signal is not very strong. The other advantage is that it has a narrower bandwidth than FM, and wider coverage compared with FM radio.

What operates in synchronous detector?

A synchronous detector consists of a reference value mixed (multiplied) with a specific modulation frequency to generate a modulated stimulus signal that is fed to the system under test (SUT) (Fig. 1). The SUT output is again mixed with the same modulation frequency.

Which are the two methods of AM generation?

AM generation involves mixing of a carrier and an information signal. In low level modulation, the message signal and carrier signal are modulated at low power levels and then amplified. The advantage of this technique is that a small audio amplifier is sufficient to amplify the message signal.

What is the principle of AM demodulation?

An AM signal encodes the information into the carrier wave by varying its amplitude in direct sympathy with the analogue signal to be sent. There are two methods used to demodulate AM signals: The envelope detector is a very simple method of demodulation that does not require a coherent demodulator.

What is coherent detection?

Coherent detection allows information to be encoded with two degrees of freedom, which increases the amount of information per channel. From: Optical Fiber Telecommunications VII, 2020.

What is asynchronous demodulation?

Asynchronous demodulation uses simulated reference signals to generate the quadrature signals for demodulation. These simulated signals are not locked in phase with the signal to be demodulated and can experience frequency mismatch.

Which devices did we use for AM demodulation?

A diode detector is the simplest device used for AM demodulation. A diode detector is built with a diode and a few other components. Modems are used for both modulation and demodulation.

Why envelope detector is mostly used in AM detection?

Such a device is often used to demodulate AM radio signals because the envelope of the modulated signal is equivalent to the baseband signal.

What is amplitude modulation detection?

A device for recovering information from an amplitude-modulated (AM) electrical signal. Such a signal is received, usually at radio frequency, with information impressed in one of several forms.

What are the types of AM?

What is the range of AM frequencies?

The AM band in the United States covers frequencies from 540 kHz up to 1700 kHz, in 10 kHz steps (540, 550, 560 ... 1680, 1690, 1700). 530 kHz in the United States is not available for broadcast use, but is reserved for the use of very low powered Travelers' Information Stations.

What is AM modulation and demodulation?

Modulation is the process of influencing data information on the carrier, while demodulation is the recovery of original information at the distant end of the carrier. A modem is an equipment that performs both modulation and demodulation.

Where is amplitude modulation used?

Amplitude modulation is mostly used in the form of electronic communication. Currently, this technique is used in many areas of communication such as in portable two-way radios; citizens band radio, VHF aircraft radio and in modems for computers.

Is coherent and synchronous same?

If two synchronous signals have the same static phase they will be coherent.

What is coherent and non coherent?

Coherent sources are sources of light that emit waves which have zero or constant phase difference and same frequency. Incoherent sources are sources of light that emit waves which have random frequencies and phase differences.

Is ask coherent or non coherent?

ASK demodulation can be done in two ways. They are, Coherent detection (Synchronous demodulation) Noncoherent Detection (Asynchronous demodulation)